In a manufacturing process of a semiconductor device and a magnetic disk, an electron beam length measuring device for measuring a shape and dimensions of a pattern formed on a sample and an electron beam inspection device for inspecting the presence or absence of defects are used. These devices irradiate a charged particle beam (hereinafter referred to as a primary beam) such as an electron beam and an ion beam on the sample and obtain a signal of secondary charged particles (hereinafter referred to as a secondary beam) such as generated secondary electrons. As the charged particle beam device, conventionally, a so-called a scanning electron microscope (SEM) type device, which scans a sample by a primary beam narrowed down to a point, is used. The SEM type device has characteristics that it takes a long time to obtain an image because scanning of the primary beam is performed two-dimensionally to obtain an image, so that it is an object to improve a speed to process a sample, that is, to improve an inspection speed. To achieve the object, a multi-beam type charged particle beam device which uses multiple beams is proposed (see Patent Literatures 1, 2, and 3).
For example, Patent Literature 1 discloses a multi-beam type electron beam inspection device which divides an electron beam emitted from a single electron gun into multiple beams, focuses the multiple beams individually by lenses arranged in an array to form plural beams, and irradiates the plural beams onto a sample and scans the sample by using a single optical element.
The multi-beam type charged particle beam device can obtain information on a sample several times faster than an SEM type device by using plural beams, and the larger the number of the beams is, the faster the inspection speed is. However, in a multi-beam type device, it is difficult to freely change the irradiation condition such as the amount of current irradiated onto a sample, the incident energy, and the size of the field of view when compared with a conventional SEM type device which uses a single beam (hereinafter referred to as a single beam type device). Therefore, the single beam type device may be more effective than the multi-beam type device depending on the sample. For example, in a memory test, an area to be tested is limited to a memory portion in a wafer, so that the advantage of the multi-beam type device, which can irradiate beams onto plural areas at the same time and obtain an image of a large area, cannot be utilized. In this case, to improve the test speed, an irradiation condition in which the amount of current to be irradiated is increased and a deflection width of the beam is decreased should be employed. Therefore, the single beam type device, which can change the irradiation condition more flexibly than the multi-beam type device, is more effective. As described above, if only the multi-beam type device is used, it is not necessarily possible to perform an efficient inspection.